ABSTRACT & COMMENTARY
Meta-Analysis Concludes Probiotics Effectively Reduce IBS Symptoms Research sheds light on strains and dosage REFERENCE
Liang D, Longgui N, Guoqiang X. Efficacy of different probiotic protocols in irritable bowel syndrome: a network meta-analysis. Medicine (Baltimore). 2019;98(27):e16068. OBJECTIVE
A meta-analysis designed to assess efficacy of the different types of probiotic protocols used to treat irritable bowel syndrome (IBS) symptoms. METHOD
The authors searched various databases including PubMed, Medline, Embase, Web of Science, and Cochrane Central Register of Controlled Trials between January 2006 and April 2019. They analyzed a total of 14 placebo-controlled randomized trials that featured 1,695 patients. In this analysis, the 2 primary multistrain protocols featured in the studies showing efficacy were: DUO = Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus rhamnosus, Bifidobacterium breve, Bifidobacterium lactis, Bifidobacterium longum, and Streptococcus thermophilus Pro = Bifidobacterium lactis Bb12, Lactobacillus acidophilus La5, Lactobacillus delbruecki subsp bulgaricus LBY-27, and Streptococcus thermophilus STY-31 KEY FINDINGS
The researchers found that protocols with a daily dose of 1010 colony-forming units (CFU) that combined Lactobacillus and Bifidobacterium strains were more effective than single strains or overdosing protocols. The DUO protocol demonstrated the most efficacy with diarrhea-type IBS, while Pro was more effective for undifferentiated-type IBS. Researchers also considered the probiotic protocols safe, with adverse events not statistically different from placebo.
PRACTICE IMPLICATIONS Rome Criteria are used to diagnose and classify functional gastrointestinal disorders such as IBS. Rome IV is the most recent version of these criteria and changed the term from functional gastrointestinal disorders to disorders of gut-brain interaction (DGBI); of these, IBS is the most common worldwide.1 While IBS prevalence has grown considerably, it may be even more common than previously thought due to self-diagnosis and self-management. Interestingly, a 2019 online survey that compared Rome IV–based IBS to self-diagnosed IBS found that nearly 69% of the survey respondents met the Rome IV criteria, but only 21% of the respondents were consulting a physician for their symptoms.2
By Ronald Hoffman, MD, and Karolyn A. Gazella The fact that this meta-analysis identified which probiotic strain combinations were effective at relieving symptoms of the different IBS classifications is clinically helpful. This analysis also confirms that multistrain probiotic formulations are more effective than a single strain, which is something that many clinicians have seen in their practice.
The issue of high doses is also important and relates to the intended clinical use of the probiotic formulation. In this meta-analysis, dosages of more than 1010 CFU were not more effective at treating IBS symptoms. Some research indicates high-dose probiotics can actually promote bacterial proliferation that exacerbates GI symptoms. This was the case in a 2018 Based on data from the International study featuring patients with small Classification of Diseases, Tenth intestinal bacterial overgrowth (SIBO) Revision (ICD-10), IBS is classified who found an increase in symptoms 5 as a functional disorder of the large including brain fog, gas, and bloating. intestine that causes abdominal pain, Results of this meta-analysis are cramping, bloating, and changes in consistent with another analysis bowel habits that can include diarrhea, published by Dale et al in 2019 in the constipation, or alternating diarrhea journal Nutrients.6 In that analysis, 11 and constipation.3 In addition, based randomized placebo-controlled trials on Rome IV classification, IBS can of probiotics were evaluated, with 7 of present with distinct bowel patterns:4 the studies finding significant improvement in IBS symptoms. That analysis 1. Diarrhea predominant (IBS-D) also showed that multistrain supple2. Constipation predominant (IBS-C) ments were more effective than single 3. Mixed diarrhea and constipation strain. All of the studies that showed (IBS-M) benefit with the multistrain probiotics 4. Unclassified and not fitting into any used 1 or both of Lactobacillus spp of the 3 subtypes (IBS-U) (continued on page 8)
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